Former NASA Engineer Says He's Invented a Thruster That Doesn't Require Propell | Hacker News Reader

Former NASA Engineer Says He's Invented a Thruster That Doesn't Require Propell

futurism.com

12 pointszhengiszen19 comments

"Stumbling upon an entirely new force of nature"

Seems very unlikely.

And it isn’t even the journalist being a numpty—Buhler is directly quoted as hailing his “discovery of a New Force” [1].

Aside: is there a term for people capitalising random words as if it grants gravitas?

[1] https://thedebrief.org/nasa-veterans-propellantless-propulsi...

https://tvtropes.org/pmwiki/pmwiki.php/Main/CapitalLettersAr...

Pretty common in scifi and fantasy books

And such an extraordinary claim would require extraordinary evidence.

I have a simple test for evaluating these kinds of news items. If their claims are correct, it will be Front Page News worldwide within a short time frame. If not,it'll quickly go the way of cold fusion.

Wasn't cold fusion on the front page news worldwide within a short timeframe?

What about bitcoin a decade ago?

For sure "Established Publications" have some protocols to pass sensitive informations to relative government agencies.

Any propellant-less thruster that uses a constant amount of power and generates constant acceleration (beyond that of a "photon rocket", https://en.wikipedia.org/wiki/Photon_rocket) would violate the second law of thermodynamics. And if it does "work", then it becomes an infinite energy source.

E.g. Let say the thruster uses 100W (100 J/s) and generated a thrust of 1N and the whole thing weighs 1kg. Look at how the kinetic energy (KE) changes with time.

    Time 0: v = 0 m/s, KE = 0J
    Time 1: v = 1 m/s, KE = 1J (delta = 1J)
    Time 2: v = 2 m/s, KE = 4J (delta = 3J)
    Time 3: v = 3 m/s, KE = 9J (delta = 6J)
    ...
    Time 50: v = 50 m/s, KE = 2500 J 
    Time 51: v = 51 m/s, KE = 2601 J (delta = 101 J) <-- This is more than the 100 J that was put in
    Time 52: v = 52 m/s, KE = 2704 J (delta = 103 J) <-- Also more than the 100 J that was put in etc.

Depending on the mass and thrust level, the "time to free energy" varies. So, any such thruster rigged up to an electric generator will eventually generate infinite power.

Color me skeptical.

Well, a solar sail is propellant-less and has constant acceleration under technically a constant amount of power. The power source is external.

Also magsails, electric charge sails, gravity assists (which could be seen as a gravity well sail) can have constant acceleration for a period of time. There are these more exotic methods where a drive interacts with its surrounding medium and the system is open, not self-contained.

I don’t know if it’s the case that some method of this kind has been discovered. But in theory, you can push yourself off of anything that repels, pull yourself towards anything that attracts, or receive momentum from anything that has it in an open system.

Every electric and magnetic charge you come across in space, you could use in theory, if you were yourself appropriately charged in that moment. This could use a lot of power and therefore a lot of work over time, and may not even be efficient. But it would still meet the propellantless criterium. It’s a bit sci-fi, of course. But probably not physically impossible.

We humans propel ourselves without a propellant every day when we walk because we operate in an open system where there is a surrounding medium to grasp and pull or push against.

Em drive and some other similar stuff were suggesting that they can make a force in a closed system, not through an interaction with a surrounding medium within which the truster exists, nor through expelling own propellant. It suggested a reactionless drive, which is not considered possible. But propellentless is very possible.

> Well, a solar sail is propellant-less and has constant acceleration under technically a constant amount of power

I guess I should have said reaction-less and not propellant-less. A solar sail is not a reaction-less drive. The momentum/energy is conserved in the system of solar sails + photons. There is no free lunch thre.

I agree with your objection, but if it were in all unlikelihood true, maybe the universe would compensate for the energy imbalance in some new way (exploding or melting the source, refusing to go faster than input power dictates, just polarizing the electrons in place, etc) that itself could be useful somehow.

Mild correction: I forgot a factor of 2 in the KE calculation. But the point still stands.

Also it should have said "reaction-less" instead of propellant-less.

Previous discussion here: https://news.ycombinator.com/item?id=40097637

This unfortunately looks like little more than hot air.

I'm not sure how useful thruster would be that produces barely measurable thrust. The criteria should be that the thruster has obvious thrust.

The other question is how efficient it is or what is the power to weight ratio. Not throwing out reaction mass is nice, but it needs power and that power needs to be generated by fuel. If it doesn't save overall fuel or is heavy, it doesn't matter if doesn't need propellant.

On earth, not much. In interstellar space, could be useful.

Where do these inventors come from? They seem to follow a very narrow path. (1) Announce that they've invented something that breaks the known laws of physics (2) Refuse to even make a simple youtube video of it in action (presumably this "unknown force" interferes with video recorders?) (3) Never publish anything about it again, never share any plans, insist that they're looking for funding still, somehow, unlikely though that is to happen since they can't be bothered to show any proof.

These are as credible as bigfoot sightings, but I don't see a lot of bigfoot sightings mentioned on HN.

I got cautiously excited about the EmDrive. Not this time. I'll believe it when they start launching commercial satellites that use it instead of normal thrusters.

I was excited about the EM drive as well. Not that I really expected it to work, but if it did crazy things would happen.

Just put it in a bucket of, “Almost certainly not real, but how cool would it be if it did?”

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